cairo/xrgstate.c

/*
 * $XFree86: $
 *
 * Copyright <EFBFBD> 2002 Carl D. Worth
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the name of Carl
 * D. Worth not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior
 * permission.  Carl D. Worth makes no representations about the
 * suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * CARL D. WORTH DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS, IN NO EVENT SHALL CARL D. WORTH BE LIABLE FOR ANY SPECIAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
 * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdlib.h>
#include <math.h>

#include "xrint.h"

XrGState *
XrGStateCreate(Display *dpy)
{
    XrGState *gstate;

    gstate = malloc(sizeof(XrGState));

    if (gstate) {
	XrGStateInit(gstate, dpy);
    }

    return gstate;
}

void
XrGStateInit(XrGState *gstate, Display *dpy)
{
    gstate->dpy = dpy;

    gstate->operator = XR_GSTATE_OPERATOR_DEFAULT;

    gstate->tolerance = XR_GSTATE_TOLERANCE_DEFAULT;

    gstate->winding = XR_GSTATE_WINDING_DEFAULT;

    gstate->line_width = XR_GSTATE_LINE_WIDTH_DEFAULT;
    gstate->line_cap = XR_GSTATE_LINE_CAP_DEFAULT;
    gstate->line_join = XR_GSTATE_LINE_JOIN_DEFAULT;
    gstate->miter_limit = XR_GSTATE_MITER_LIMIT_DEFAULT;
    gstate->dashes = 0;
    gstate->ndashes = 0;
    gstate->dash_offset = 0.0;

    gstate->solidFormat = XcFindStandardFormat(dpy, PictStandardARGB32);
    gstate->alphaFormat = XcFindStandardFormat(dpy, PictStandardA8);

    XrSurfaceInit(&gstate->surface, dpy);

    XrSurfaceInit(&gstate->src, dpy);
    XrColorInit(&gstate->color);
    XrSurfaceSetSolidColor(&gstate->src, &gstate->color, gstate->solidFormat);

    XrTransformInit(&gstate->ctm);
    XrTransformInit(&gstate->ctm_inverse);

    XrPathInit(&gstate->path);

    XrPenInitEmpty(&gstate->pen_regular);
}

XrError
XrGStateInitCopy(XrGState *gstate, XrGState *other)
{
    XrError err;
    
    *gstate = *other;
    if (other->dashes) {
	gstate->dashes = malloc (other->ndashes * sizeof (double));
	if (gstate->dashes == NULL)
	    return XrErrorNoMemory;
	memcpy (gstate->dashes, other->dashes, other->ndashes * sizeof (double));
    }

    XrSurfaceInit(&gstate->src, gstate->dpy);
    XrSurfaceSetSolidColor(&gstate->src, &gstate->color, gstate->solidFormat);

    err = XrPathInitCopy(&gstate->path, &other->path);
    if (err)
	goto CLEANUP_DASHES;

    err = XrPenInitCopy(&gstate->pen_regular, &other->pen_regular);
    if (err)
	goto CLEANUP_PATH;

    return err;

  CLEANUP_PATH:
    XrPathDeinit(&gstate->path);
  CLEANUP_DASHES:
    free (gstate->dashes);
    gstate->dashes = NULL;

    return err;
}

void
XrGStateDeinit(XrGState *gstate)
{
    XrColorDeinit(&gstate->color);
    XrSurfaceDeinit(&gstate->src);
    XrSurfaceDeinit(&gstate->surface);
    XrTransformDeinit(&gstate->ctm);
    XrTransformDeinit(&gstate->ctm_inverse);

    XrPathDeinit(&gstate->path);

    XrPenDeinit(&gstate->pen_regular);

    if (gstate->dashes) {
	free (gstate->dashes);
	gstate->dashes = NULL;
    }
}

void
XrGStateDestroy(XrGState *gstate)
{
    XrGStateDeinit(gstate);
    free(gstate);
}

XrGState*
XrGStateClone(XrGState *gstate)
{
    XrError err;
    XrGState *clone;

    clone = malloc(sizeof(XrGState));
    if (clone) {
	err = XrGStateInitCopy(clone, gstate);
	if (err) {
	    free(clone);
	    return NULL;
	}
    }

    return clone;
}

void
XrGStateSetDrawable(XrGState *gstate, Drawable drawable)
{
    XrSurfaceSetDrawable(&gstate->surface, drawable);
}

void
XrGStateSetVisual(XrGState *gstate, Visual *visual)
{
    XrSurfaceSetVisual(&gstate->surface, visual);
}

void
XrGStateSetFormat(XrGState *gstate, XrFormat format)
{
    XrSurfaceSetFormat(&gstate->surface, format);
}

void
XrGStateSetOperator(XrGState *gstate, XrOperator operator)
{
    gstate->operator = operator;
}

void
XrGStateSetRGBColor(XrGState *gstate, double red, double green, double blue)
{
    XrColorSetRGB(&gstate->color, red, green, blue);
    XrSurfaceSetSolidColor(&gstate->src, &gstate->color, gstate->solidFormat);
}

void
XrGStateSetTolerance(XrGState *gstate, double tolerance)
{
    gstate->tolerance = tolerance;
    if (gstate->tolerance < XR_GSTATE_TOLERANCE_MINIMUM)
	gstate->tolerance = XR_GSTATE_TOLERANCE_MINIMUM;
}

void
XrGStateSetAlpha(XrGState *gstate, double alpha)
{
    XrColorSetAlpha(&gstate->color, alpha);
    XrSurfaceSetSolidColor(&gstate->src, &gstate->color, gstate->solidFormat);
}

void
XrGStateSetLineWidth(XrGState *gstate, double width)
{
    gstate->line_width = width;
}

void
XrGStateSetLineCap(XrGState *gstate, XrLineCap line_cap)
{
    gstate->line_cap = line_cap;
}

void
XrGStateSetLineJoin(XrGState *gstate, XrLineJoin line_join)
{
    gstate->line_join = line_join;
}

XrError
XrGStateSetDash(XrGState *gstate, double *dashes, int ndash, double offset)
{
    if (gstate->dashes) {
	free (gstate->dashes);
    }
    
    gstate->dashes = malloc (ndash * sizeof (double));
    if (!gstate->dashes) {
	gstate->ndashes = 0;
	return XrErrorNoMemory;
    }
    gstate->ndashes = ndash;
    memcpy (gstate->dashes, dashes, ndash * sizeof (double));
    gstate->dash_offset = offset;
    return XrErrorSuccess;
}

void
XrGStateSetMiterLimit(XrGState *gstate, double limit)
{
    gstate->miter_limit = limit;
}

void
XrGStateTranslate(XrGState *gstate, double tx, double ty)
{
    XrTransform tmp;

    XrTransformInitTranslate(&tmp, tx, ty);
    XrTransformMultiplyIntoRight(&tmp, &gstate->ctm);

    XrTransformInitTranslate(&tmp, -tx, -ty);
    XrTransformMultiplyIntoLeft(&gstate->ctm_inverse, &tmp);
}

void
XrGStateScale(XrGState *gstate, double sx, double sy)
{
    XrTransform tmp;

    XrTransformInitScale(&tmp, sx, sy);
    XrTransformMultiplyIntoRight(&tmp, &gstate->ctm);

    XrTransformInitScale(&tmp, 1/sx, 1/sy);
    XrTransformMultiplyIntoLeft(&gstate->ctm_inverse, &tmp);
}

void
XrGStateRotate(XrGState *gstate, double angle)
{
    XrTransform tmp;

    XrTransformInitRotate(&tmp, angle);
    XrTransformMultiplyIntoRight(&tmp, &gstate->ctm);

    XrTransformInitRotate(&tmp, -angle);
    XrTransformMultiplyIntoLeft(&gstate->ctm_inverse, &tmp);
}

void
XrGStateNewPath(XrGState *gstate)
{
    XrPathDeinit(&gstate->path);
}

XrError
XrGStateAddPathOp(XrGState *gstate, XrPathOp op, XPointDouble *pt, int num_pts)
{
    int i;
    XrError err;
    XPointFixed *pt_fixed;

    switch (op) {
    case XrPathOpMoveTo:
    case XrPathOpLineTo:
    case XrPathOpCurveTo:
	for (i=0; i < num_pts; i++) {
	    XrTransformPoint(&gstate->ctm, &pt[i]);
	}
	break;
    case XrPathOpRelMoveTo:
    case XrPathOpRelLineTo:
    case XrPathOpRelCurveTo:
	for (i=0; i < num_pts; i++) {
	    XrTransformPointWithoutTranslate(&gstate->ctm, &pt[i]);
	}
	break;
    case XrPathOpClosePath:
	break;
    }

    pt_fixed = malloc(num_pts * sizeof(XPointFixed));
    if (pt_fixed == NULL) {
	return XrErrorNoMemory;
    }

    for (i=0; i < num_pts; i++) {
	pt_fixed[i].x = XDoubleToFixed(pt[i].x);
	pt_fixed[i].y = XDoubleToFixed(pt[i].y);
    }

    err = XrPathAdd(&gstate->path, op, pt_fixed, num_pts);

    free(pt_fixed);

    return err;
}

XrError
XrGStateAddUnaryPathOp(XrGState *gstate, XrPathOp op, double x, double y)
{
    XPointDouble pt;

    pt.x = x;
    pt.y = y;

    return XrGStateAddPathOp(gstate, op, &pt, 1);
}

XrError
XrGStateClosePath(XrGState *gstate)
{
    return XrPathAdd(&gstate->path, XrPathOpClosePath, NULL, 0);
}

XrError
XrGStateStroke(XrGState *gstate)
{
    XrError err;

    static XrPathCallbacks cb = {
	XrStrokerAddEdge,
	XrStrokerAddSpline,
	XrStrokerDoneSubPath,
	XrStrokerDonePath
    };

    static XrPathCallbacks cb_dash = {
	XrStrokerAddEdgeDashed,
	XrStrokerAddSpline,
	XrStrokerDoneSubPath,
	XrStrokerDonePath
    };
    XrPathCallbacks *cbs = gstate->dashes ? &cb_dash : &cb;

    XrStroker stroker;
    XrTraps traps;

    XrPenInit(&gstate->pen_regular, gstate->line_width / 2.0, gstate);

    XrTrapsInit(&traps);
    XrStrokerInit(&stroker, gstate, &traps);

    err = XrPathInterpret(&gstate->path, XrPathDirectionForward, cbs, &stroker);
    if (err) {
	XrStrokerDeinit(&stroker);
	XrTrapsDeinit(&traps);
	return err;
    }

    XcCompositeTrapezoids(gstate->dpy, gstate->operator,
			  gstate->src.xcsurface, gstate->surface.xcsurface,
			  gstate->alphaFormat,
			  0, 0,
			  traps.xtraps,
			  traps.num_xtraps);

    XrStrokerDeinit(&stroker);
    XrTrapsDeinit(&traps);

    XrGStateNewPath(gstate);

    return XrErrorSuccess;
}

XrError
XrGStateFill(XrGState *gstate)
{
    XrError err;
    static XrPathCallbacks cb = {
	XrFillerAddEdge,
	XrFillerAddSpline,
	XrFillerDoneSubPath,
	XrFillerDonePath
    };

    XrFiller filler;
    XrTraps traps;

    XrTrapsInit(&traps);
    XrFillerInit(&filler, gstate, &traps);

    err = XrPathInterpret(&gstate->path, XrPathDirectionForward, &cb, &filler);
    if (err) {
	XrFillerDeinit(&filler);
	XrTrapsDeinit(&traps);
	return err;
    }

    XcCompositeTrapezoids(gstate->dpy, gstate->operator,
			  gstate->src.xcsurface, gstate->surface.xcsurface,
			  gstate->alphaFormat,
			  0, 0,
			  traps.xtraps,
			  traps.num_xtraps);

    XrFillerDeinit(&filler);
    XrTrapsDeinit(&traps);

    XrGStateNewPath(gstate);

    return XrErrorSuccess;
}